title: Mining the O-mannose glycoproteome reveals cadherins as major O-mannosylated glycoproteins.
abstract: The metazoan O-mannose (O-Man) glycoproteome is largely unknown. It has been shown that up to 30% of brain O-glycans are of the O-Man type, but essentially only alpha-dystroglycan (α-DG) of the dystrophin-glycoprotein complex is well characterized as an O-Man glycoprotein. Defects in O-Man glycosylation underlie congenital muscular dystrophies and considerable efforts have been devoted to explore this O-glycoproteome without much success. Here, we used our SimpleCell strategy using nuclease-mediated gene editing of a human cell line (MDA-MB-231) to reduce the structural heterogeneity of O-Man glycans and to probe the O-Man glycoproteome. In this breast cancer cell line we found that O-Man glycosylation is primarily found on cadherins and plexins on β-strands in extracellular cadherin and Ig-like, plexin and transcription factor domains. The positions and evolutionary conservation of O-Man glycans in cadherins suggest that they play important functional roles for this large group of cell adhesion glycoproteins, which can now be addressed. The developed O-Man SimpleCell strategy is applicable to most types of cell lines and enables proteome-wide discovery of O-Man protein glycosylation.
authors.affiliation: Copenhagen Center for Glycomics and Department of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark.
authors.forename: Malene B
authors.initials: MB
authors.lastname: Vester-Christensen
authors.forename: Adnan
authors.initials: A
authors.lastname: Halim
authors.forename: Hiren Jitendra
authors.initials: HJ
authors.lastname: Joshi
authors.forename: Catharina
authors.initials: C
authors.lastname: Steentoft
authors.forename: Eric P
authors.initials: EP
authors.lastname: Bennett
authors.forename: Steven B
authors.initials: SB
authors.lastname: Levery
authors.forename: Sergey Y
authors.initials: SY
authors.lastname: Vakhrushev
authors.forename: Henrik
authors.initials: H
authors.lastname: Clausen
mesh_terms: D015820:Cadherins / Q000737:chemistry*; D015815:Cell Adhesion Molecules / Q000737:chemistry; D045744:Cell Line, Tumor; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D006801:Humans; D008358:Mannose / Q000737:chemistry*; D013058:Mass Spectrometry; D009419:Nerve Tissue Proteins / Q000737:chemistry; D020543:Proteome / Q000737:chemistry*; D040901:Proteomics / Q000379:methods*
chemical_list: D015820:Cadherins; D015815:Cell Adhesion Molecules; D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D020543:Proteome; C091529:plexin; D008358:Mannose
keywords: O-glycosylation; Orbitrap; POMGnT1; glycoproteomics; mass spectrometry